Soil respiration fluxes and controlling factors in temperate forest and cropland ecosystems [Elektronische Ressource] / von Fernando Esteban Moyano

Nano

Sujets

• Biologie

Informations

• Publié par: eberhard_karls_universitat_tubingen
• Publié le: 01 janvier 2008
• Nombre de lectures: 61
• Langue: Deutsch
• Poids de l'ouvrage: 3 Mo

Extrait

Soil Respiration Fluxes and Controlling Factors
in Temperate Forest and Cropland Ecosystems







Dissertation
zur Erlangung des Grades eines Doktors der Naturwissenschaften



der Geowissenschaftlichen Fakultät der
Eberhard Karls Universität Tübingen



von

Fernando Esteban Moyano
aus Rio Tercero (Argentinien)


2008 ii


























Tag der mündlichen Prüfung: 19.12.2007


Dekan: Prof. Dr. Peter Grathwohl

1. Berichtertatter: Prof. Dr. Thomas Scholten

2. Berichtertatter: Priv.-Doz. Dr. Werner L. Kutsch
iii
Table of Contents

1. INTRODUCTION AND OVERVIEW ........................................................................................... 1
1.1. THE ROLE OF SOIL RESPIRATION IN THE CARBON CYCLE ............................................................. 1
1.2. MEASURING SOIL RESPIRATION .................................................................................................... 3
1.3. STUDY OBJECTIVES ....................................................................................................................... 5
1.4. STUDY APPROACH AND GENERAL METHODOLOGY ...................................................................... 6
1.5. SUMMARY OF RESULTS ............................................................................................................... 12
1.6. CONCLUSIONS AND OUTLOOK .................................................................................................... 18
1.7. THESIS CHAPTERS ....................................................................................................................... 21
REFERENCES ............................................................................................................................................. 21
2. RESPONSE OF MYCORRHIZAL, RHIZOSPHERE AND SOIL HETEROTROPHIC
RESPIRATION TO TEMPERATURE AND PHOTOSYNTHESIS IN A BARLEY FIELD ........... 25
2.1. INTRODUCTION ........................................................................................................................... 26
2.2. METHODS .................................................................................................................................... 28
2.3. RESULTS ..................................................................................................................................... 33
2.4. DISCUSSION ................................................................................................................................ 39
2.5. CONCLUSIONS ............................................................................................................................. 44
ACKNOWLEDGMENTS ................................................................................................................................ 45
REFERENCES ............................................................................................................................................. 45
3. SOIL RESPIRATION FLUXES IN RELATION TO PHOTOSYNTHETIC ACTIVITY IN
BROAD-LEAF AND NEEDLE-LEAF FOREST STANDS ................................................................. 49
3.1. INTRODUCTION ........................................................................................................................... 50
3.2. METHODS .................................................................................................................................... 52
3.3. RESULTS ..................................................................................................................................... 57
3.4. DISCUSSION ................................................................................................................................ 63
3.5. CONCLUSIONS ............................................................................................................................. 66
ACKNOWLEDGMENTS ................................................................................................................................ 67
REFERENCES ............................................................................................................................................. 67
4. EXPLORING THE EFFECTS OF SPATIALLY VARIABLE SOIL FACTORS ON
MYCORRHIZOSPHERE AND MICROBIAL RESPIRATION ......................................................... 71
4.1. INTRODUCTION ........................................................................................................................... 72
4.2. MATERIALS AND METHODS ........................................................................................................ 75
4.3. RESULTS ..................................................................................................................................... 78
iv
4.4. DISCUSSION ................................................................................................................................ 84
4.5. CONCLUSIONS ............................................................................................................................ 89
ACKNOWLEDGMENTS ............................................................................................................................... 91
REFERENCES ............................................................................................................................................. 91
5. RESPIRATION FROM ROOTS AND THE MYCORRHIZOSPHERE: INFLUENCING
FACTORS AND MEASUREMENT METHODS ................................................................................. 97
5.1. INTRODUCTION ........................................................................................................................... 97
5.2. ROOT AND MYCORRHIZOSPHERE RESPIRATION ....................................................................... 101
5.2.1. Eco-Physiology of Root Respiration ................................................................................... 101
5.2.2. Regulation of Root Respiration by Plant and Environmental Factors ............................... 102
5.2.3. Rhizomicrobial and Mycorrhizal Respiration ..................................................................... 110
5.3. MEASURING ROOT AND MYCORRHIZOSPHERE RESPIRATION ................................................... 116
5.3.1. General Considerations ...................................................................................................... 117
5.3.2. Field Methods ..................................................................................................................... 119
5.3.3. Laboratory Methods ........................................................................................................... 129
5.3.4. Calculating the Q ............................................................................................................. 132 10
5.3.5. Methodology for Quantifying the Degree of Acclimation ................................................... 136
5.4. MYCORRHIZOSPHERE RESPIRATION AT THE ECOSYSTEM SCALE .............................................. 140
5.5. CONCLUDING REMARKS ........................................................................................................... 143
REFERENCES ........................................................................................................................................... 144
SYMBOLS AND ABBREVIATIONS ....................................................................................................157
SUMMARY ..............................................................................................................................................159
ZUSAMMENFASSUNG......................................................................................................................... 161
ACKNOWLEDGEMENT ......................................................................................................................165

Introduction and Overview1
1. Introduction and Overview
1.1. The Role of Soil Respiration in the Carbon Cycle
The biogeochemical cycle of carbon includes several reservoirs which differ in their size
and turnover times (Figure 1.1). The atmosphere holds about 800 gigatons (Gt) of carbon
and has the fastest turnover time with ca. 122 Gt C being taken up by the terrestrial
biosphere and 90-92 Gt C being exchanged with the surface ocean every year (Sabine et
al. 2003).

Figure 1.1: The global carbon cycle. Values are given in Gt C. Bold prints are reservoirs and normal prints
are fluxes. Mean residence times are in parentheses. DOC = dissolved organic carbon, DIC = dissolved
inorganic carbon. Source: WBGU (Schubert et al. 2006). Adapted after Schlesinger (1997); Sabine et al.,
(2003); Raven et al., (2005); NOAA-ESRL, (2006).

Carbon can remain for a period of days to several years as part of the terrestrial biomass
but will eventually be respired back to the atmosphere as CO , or it will become litter and 2
2 Soil Respiration Fluxes and Controlling Factors
form part of the pedosphere, i.e. soils. Soils, with a total global storage of approximately
1500 Gt C (Jacobson et al. 2000) hold three ti